Compositions and process

ABSTRACT

THE ZWITTERION THEREOF OR THE HEMI-SALT THEREOF; R is alkyl of not more than 4 carbon atoms; and R1 is alkyl of not more than 8 carbon atoms in association with a pharmaceutical carrier. The compounds have clindamycin-like antibacterial activity and provide particularly high concentrations of compound in the urinary tract thereby being particularly useful in treating bacterial infections of the upper and lower urinary tract as well as L-forms in the kidney. OR THE ACID ADDITION SALTS THEREOF WHEREIN Halo is chlorine, bromine, or iodine, X is a member selected from the group consisting of hydrogen, an acyl radical of an aliphatic carboxylic acid having from 2 to 18 carbon atoms, inclusive,   1&#39;&#39;-( Beta -Hydroxyethyl)-1&#39;&#39;-demethylclindamycin compounds of the formula:

nited States Patent [191 irkenmeyer Dec. 24, 1974 COMPOSITIONS AND PROCESS [75] Inventor: Robert D. Birkenmeyer, Galesburg,

Mich.

[73] Assignee: The Upjohn Company, Kalamazoo,

Mich.

[63] Continuation-impart of Ser. No. 156,099, June 23,

1971, Pat. No. 3,787,390.

[52] US. Cl. 424/180, 260/210 R [51] int. Cl A0ln 9/00 [58] Field of Search 424/180 Primary ExaminerElbert L. Roberts Attorney, Agent, or Firm-John J. Killinger; Roman Saliwanchik [57] ABSTRACT 1'-(B-Hydroxyethyl)-1 '-demethylclindamycin pounds of the formula:

com-

CHzCI-IEOH 1 on: H l Haio \lhl/ 1 l N R1 II I Ho /l i/ SR or the acid addition salts thereof wherein Halo is chorine, bromine, or iodine, X is a member selected from the group consisting of hydrogen, an acyl radical of an aliphatic carboxylic acid having from 2 to 18 carbon atoms, inclusive,

the zwitterion thereof or the hemi-salt thereof; R is alkyl of not more than 4 carbon atoms; and R is alkyl of not more than 8 carbon atoms in association with a pharmaceutical carrier.

The compounds have clindamycin-like antibacterial activity and provide particularly high concentrations of compound in the urinary tract thereby being particularly useful in treating bacterial infections of the upper and lower urinary tract as well as L-forms in the kidney.

10 Claims, No Drawings COMPOSITIONS AND PROCESS CROSS REFERENCE TO RELATED APPLICATIONS The application is a continuation in part of our copending application Ser. No. 156,099 filed June 23, 1971 now Pat. No. 3,787,390.

BRIEF SUMMARY OF THE INVENTION This invention relates to pharmaceutical compositions and is particularly directed to l-(B- hydroxyethyl)-1-demethylclindamycin compositions. These compositions in addition to having the antibacterial spectrum of clindamycin have been found to provide extremely high concentrations of the compound in the urinary tract subsequent to oral or parenteral administration. The compositions are useful in treating infections in the upper and lower urinary tract as well as for treating L-forms in the kidney.

The active ingredient of the compositions of the invention can be represented by the following structural formula:

Formula I or the acid addition salts thereof wherein Halo is chlorine, bromine, or iodine; X is a member selected from the group consisting of hydrogen, an acyl radical of an aliphatic acid having from 2 to 18 carbon atoms, inclusive,

the zwitterion thereof or the hemi-salt thereof; R is alkyl of not more than 4 carbon atoms; and R is alkyl of not more than 8 carbon atoms.

Examples of alkyl of not more than 8 carbon atoms (R are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and the isomeric forms thereof.

Examples of aliphatic carboxylic acids providing the acyl moiety are the saturated and unsaturated, straight or branched chain aliphatic carboxylic acids, for example, acetic, propionic, butyric, isobutyric, tertbutylacetic, valeric, isovaleric, caproic, caprylic, decanoic, dodecanoic, lauric, tridecoic, myristic, pentadecanoic, palmitic, margaric, stearic, undecylenic, oleic, hexynoic, heptynoic, and octynoic acids and the like.

The starting materials for the preparation of the phosphate or acylate compounds are compounds of the Formula I wherein X is hydrogen. The compounds are 6 disclosed and can be prepared by methods set forth in US. Patent application Ser. No. 156,099, filed June 23, 1971, now allowed.

DETAILED DESCRIPTION OF THE INVENTION The active derivatives of the present invention are prepared by the following steps starting with a compound of the Formula I wherein X is hydrogen:

I Protecting the 3- and 4-hydroxy groups by formation of a 3,4-alkylidene or arylidene. II Protecting the primary hydroxy by (A) tritylation or (B) silylation or (C) formation of a tetrahydrol0 pyranyl ether.

III Acylation, or phosphorylation, and IV Removal of the protective groups put on in steps I and II.

STEP 1 To protect the 3,4-hydroxy groups, a compound of the Formula I wherein X is hydrogen, advantageously as the hydrochloride salt, is first condensed with an alkyl or aryl aldehyde or ketone, with the aid of mild heat, to form the 3,4-O-alkylidene or 3,4 O-arylidene. Acid catalysis of the reaction is unnecessary if the hydrochloride Salt is used as this provides sufficient catalysis of the reaction. The reaction can be forced to completion through azeotropic removal of water by an organic solvent, for example, benzene, toluene, chloroform, ethylene chloride, and the like. The azeotropeforming solvent can be eliminated if water is removed by some other means, such as by evacuation, vaporization with an inert gas, or merely by co-distillation with a solvent which has a higher boiling point than water. The azeotrope-forming solvent is used in admixture with a highly polar solvent, such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, N-methyl pyrrolidone, and the like, in order to solubilize the starting compound hydrochloride and thus produce a homogeneous solution.

The condensation reaction can be conducted between temperatures of about 15 to 180 C.; the preferred temperatures being about 15-50 for alkylidene and 90l 10 C. for arylidene. The optimum temperature depends on the ratio of polar to non-polar solvent, and on the specific properties of the non-polar solvent, such as the boiling temperature of the azeotrope formed with water as well as the boiling point of the non-polar solvent itself according to the art. The nonpolar solvent containing moisture can be continuously removed by distillation and replaced periodically with fresh dry solvent. The water also can be removed by condensation and separation with a water trap, or a dessicant can be used, thus permitting the dried solvent to return to the reaction vessel.

The time for complete condensation as disclosed, above, varies with the solvent composition and the efficiency of removal of the water. When azeotropeforming solvents are used, as described above, the course of the reaction can be followed by measuring the amount of water liberated. Alternatively, the reaction vessel can be sampled periodically and chromatographed. With solvent combinations of benzene and dimethylformamide, reaction times of about l-16 hours can be used, with 23 hours usually being optimum. Typical alkyl ketones useful in the process are acetone, diethyl ketone, methylbutyl ketone, and the like. A variety of aromatic aldehydes can also be used in the process of the invention, for example, furfural, 5- methylfurfural, benzaldehyde, salicylaldehyde, mtolualdehyde, o-tolualdehyde, p-tolualdehyde, o-

LII

LII

chlorobenzaldehyde, m-chlorobenzaldehyde, mbromobenzaldehyde, p-bromobenzaldehyde, pmethoxybenzaldehyde, m-methoxybenzaldehyde, omethoxybenzaldehyde, 3,4-dimethoxybenzaldehyde (veratric aldehyde), p-isopropylbenzaldehyde, salicylaldehyde, p-hydroxybenzaldehyde, 3,4,5-trimethoxybenzaldehyde, piperonal, o-nitrobenzaldehyde, p-

chlorobenzaldehyde, phthaldehyde, mnitrobenzaldehyde, p-nitrobenzaldehyde, B-naphthaldehyde, pbromobenzaldehyde, o-

bromobenzaldehyde, 2,4-dichlorobenzaldehyde, vanillin, terephthaldehyde, protocatechualdehyde, and cinnamaldehyde.

Also useful are aldehydes in which the carbonyl group is separated from the aromatic moiety by one or more double bonds giving a conjugated structure of:

wherein n can be an integer of from 1-4, and Z can be one of the following substituents on the aromatic moiety:

The acetals formed by the above-disclosed process are initially isolated as crystalline hydrochloride salts. With stable acetals, for example, the 3,4-benzylidene derivatives, and 3,4-p-chlorobenzylidene derivatives, recrystallization of the hydrochlorides can be brought about with hot Methyl Cellosolve, dimethylformamide, chloroform, and the like. The less stable acetals, for example, 3,4-p-anisylidene derivative, 3,4- cinnamylidene, and 3,4-toluylidene derivative must be converted to the free base form before isolation of the acetal.

The 3,4-protected, e.g., arylidene, hydrochloride salts can be converted to the free base by mixing the salts with a basic material, for example, aqueous sodium hydroxide, a quaternary ammonium hydroxide, ammonium hydroxide, or a strong amine base. Basic ion exchange resin can be used. The insoluble arylidene base can be removed by filtration, or it can be extracted with water-immiscible solvents, for example, chloroform, methylene chloride, ethylene dichloride, ether and the like. Alternatively, the 3,4-protected hydrochloride salts can be converted to the free bases by first neutralizing the salt with a base after placing the salt in solution in a solvent such as dimethylformamide, dimethylacetamide, propylene glycol, and the like. The base can be an alkoxide, an amine, ammonia, or a solid inorganic base, for example, sodium hydroxide, potassium hydroxide, and the like. The resulting solutions of the base can be recovered from water-miscible solvents by dilution with water to the cloud point resulting in slow crystallization of the acetals. The solutions of the base in water-immiscible solvents can be recovered by dilution of the solution with a nonpolar solvent, for example, hexane, isomeric hexanes, and the like, or by simply evaporating the solvent. The latter procedure for forming the free base from the 3,4-protected hydrochloride salts is suitable for isolating the very labile acetals since a nonaqueous procedure can be employed.

Most of the 3,4-protected bases can be purified by solution of the compound in acetone, diluting the solution with ether, and then adding hexane to the cloud point to induce spontaneous crystallization.

STEP llA Trityl ethers of the 3,4-O-protected derivatives are prepared by reacting an excess of trityl halide or substituted trityl halide with the 3,4-arylidene or alkylidene derivatives from Step I in the presence of a strong base and a suitable solvent. The preferred mole ratio of trityl halide or substituted trityl halide to the 3,4-arylidene or alkylidene compound is 4: 1. Higher ratios of tritylating agent to 3,4-protected compound can be used (up to about 10:1), although increasing amounts of ditritylated by-products are formed with a large excess of tritylating agent. Lower mole ratios of tritylating agent to 3,4-protected compound (below lzl result in an incomplete reaction, as well as formation of additional unidentified by-products.

The preferred trityl halide in the above reaction is trityl chloride. However, other trityl halides and substituted trityl halides of the following formula can be used:

wherein Y is selected from the group consisting of Cl and Br and X X and X are selected from the group consisting or hydrogen, halogen, and OCH The compounds of the type in which the substituents X X and X are mono-, di-, or tri-para-chloro may be made by the methods reported by Gomberg [Ber. 37, 1633 (1904)]. The corresponding compounds in which X X and X are para-methoxy may be prepared by the methods described by Smith et al., and references therein [J. Am. Chem. Soc., 84, 430 1962), see page 436].

The preferred solvent for the tritylation is acetone. Other solvents which can be used are 2-butanone, 2- pentanone, 3-pentanone, ether, benzene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, methyl acetate, ethyl acetate, pyridine, and the like. Use of the higher boiling polar solvents, however,

tends to result in the production of additional byproducts from the reaction, whereas the lower boiling solvents do not permit a complete reaction.

The preferred base is triethylamine. Other strongly basic trialkyl amines can be used, for example, triethylenediamine, N-alkylmorpholine derivatives, tripropylamine, tributylamine, and the like. Tertiary bases having a pKa greater than 8 permit a more rapid reaction since better solubility of the 3,4-protected starting compounds is maintained. Weaker bases, such as pyridine, require longer reaction times since 3,4-protected starting compounds are largely insolubilized as the hydrochloride salt in the presence of such a base.

The reaction time is determined by several factors, for example, the boiling point of the solvent, the strength of the base, the concentration and ratio of trityl halide to 3,4-protected compound, and the polarity of the solvent. For example, with the following mole ratio of trityl chloride to anisylidene derivative to triethylamine to acetone of 72: 1 5:16:34, the preferred reaction time at reflux temperature is 24 hours. Reaction times up to 48 hours can be used although increasing amounts of di-tritylated derivatives are formed. Reaction times less than six hours result in appreciable amounts of unchanged anisylidene derivatives. With other mole ratios, the operating reaction time can range from 1 to 100 hours. The course of the reaction can be monitored by paper chromatography or thin layer chromatography (tlc) according to the art.

Upon completion of the tritylation reaction, the 1'- (trityloxyethyl)-3,4-protected derivative is precipitated by the addition of a non-polar solvent such as hexane, heptane, pentane, cyclohexane, benzene, and the like. The crude reaction product is recrystallized repeatedly from hot acetonitrile and finally from hot acetonewater (1:1) mixture to provide a pure preparation of the derivative. Other organic solvents can be used for recrystallization, for example, Z-butanone, 3- pentanone, n-propanol, 2-propanol, butyl acetate, benzene, butyronitirle, N,N-dimethylformamide-water, N,N-dimethylacetamide-water, methanol-water, ethanol-water, and the like.

STEP 11B Alternatively, the primary hydroxyl of the hydroxyethyl group on the pyrrolidine nitrogen atom may be protected before Step 111 by silylation, for instance with a trimethylsilyl group, according to the art. The silyla' tion is carried out by reacting the 3,4-protected compound with a silylating agent in a suitable solvent. A typical procedure is to react the 3,4-protected compound with excess hexamethylsilazane (a bifunctional silylating agent) with trimethylchlorosilane as a catalyst, in pyridine solution. The reaction occurs readily at ambient temperature and results in the formation of a trimethylsilyl-protected derivative. Other operable silylating agents, according to the art, include for example diorganomonochlorosilanes such as diphenylmonochlorosilane, dibenzylmonochlorosilane and methylphenylmonochlorosilane as in British Patent 822,970, referred to in Chemical Abstracts 44, 658 (1950); and other trisubstituted chlorsilanes [Cram and Hammond, Organic Chemistry page 257 (1959); Sneed and Brasted, Comprehensive lnorg. Chem. 7, 111 (1958); Roberts and Caserio, Basic Principles of Org. Chem, page 1182 (1964)] from trimethylto tribenzylchlorosilanes. An alternative suitable solvent is piperidine. For purification of the silyl ethers the reaction mixture is evaporated to dryness under vacuum, taken up in chloroform, washed with water, filtered through silica gel and evaporated. Other purification according to the art is also possible, and upon completion of 2- substitution according to Step III, the protective silyl group is removed simultaneously with the 3,4- protective group by acid hydrolysis, for example by treatment with acetic acid-water as given below.

STEP llC A third method for protecting the primary hydroxyl of the hydroxyethyl group on the pyrrolidine nitrogen atom is by reacting with dihydropyran to form a tetrahydropyranyl ether.

The reaction is carried out at room temperature in an inert solvent such as diethyl ether with a few drops of concentrated hydrochloric acid as a catalyst. After stirring for several hours the acid is neutralized with sodium hydroxide and the solvent evaporated under vacuum. The solid residue may be purified by crystallization or chromatography but is usually pure enough to use in the following step without further treatment.

STEP lll ACYLATION The 3,4-protected clindamycin compounds can be acylated by processes already well known in the art, for example, by reacting with an acylating agent in the presence of an acidbinding agent, for example, a tertiary amine, to produce a 3,4-protected 2'acylate. Suitable acylating agents include acid halides and acid anhydrides. Suitable tertiary amines include heterocyclic amines such as pyridine, quinoline, and isoquinoline; trialkylamines such as trimethylamine, triethylamine, triisopropylamine, and the like; N,N-dialkylanilines such as dimethylaniline, diethylaniline, and the like; and N-alkylpiperidines such as N-ethylpiperidine, N- methylpiperidine, and the like. The preferred base is pyridine.

The acylation is advantageously conducted by treat ing a solution of a 3,4-protected clindamycin compound or a suspension of the hydrochloride in a mixture of an inert solvent and a tertiary amine, for example, pyridine, with an acylating agent, for example, acyl chloride, and cooling the reaction mixture to prevent side reactions. Advantageously, the reaction is conducted in pyridine at low temperature, preferably -20 to C., however higher or lower temperatures can be used. Suitable inert solvents include chloroform, dimethylformamide, dimethylacetamide, acetonitrile, methylene chloride, acetone, and dioxane.

STEP lll PHOSPHORYLATION The hydroxyl-protected compound can be phosphorylated by processes already well known in the art, for example, by reacting it with a phosphorylating agent in the presence of an acid-binding agent; for example, a tertiary amine, to produce 1'-demethyl-l (trityloxyethyl)-3,4-O-protected clindamycin 2- phosphate. Suitable phosphorylating agents include phosphoryl trichloride (POCl dianilinophosphorochloridate, anilinophosphorodichloridate, di-t-butylphosphorochloridate, dimorpholinophosphorobromidate, and cyanoethylphosphate plus dichclohexylcarbodiimide. Suitable tertiary amines include heterocyclic amines such as pyridine, quinoline, and isoquinoline, trialkylamines such as trimethylamine, triethylam- 7 ine, triisopropylamine, and the like; N,N- dialkylanilines such as dimethylaniline, diethylaniline, and the like; and N-alkylpiperidines such as N- ethylpiperidine, N-methylpiperidine, and the like. The preferred base is pyridine.

The phosphorylation is advantageously conducted by treating a solution of the hydroxyl-protected compound in a tertiary amine, for example, pyridine, with a phosphorylating agent, for example, phosphoryl chloride, and cooling the reaction mixture to prevent excessive side reactions. Advantageously, the reaction is conducted in pyridine at low temperatures, preferably 38 to 42 C. Temperatures between 50 C. and +l C. are allowable although appreciable amounts of side-products sometimes arise at higher temperatures. The resulting 2-phosphorodichloridate is hydrolyzed (quenched) with water to the corresponding phosphate ester at temperatures between 40 C. and C. Low temperatures are preferred in order to minimize side-products. Thus, upon reacting l-demethyl-l -(B- trityloxyethyl)-3,4-O-protected clindamycin in the presence of a tertiary amine with at least 1 mole of phosphorylating agent, there is obtained l-demethyll-(B-trityloxyethyl)-3,4-O-protected clindamycin 2- phosphate.

The 2-phosphate can be prepared from l-demethyll'-(B-trityloxyethyl)-3,4-O-arylidene clindamycin 2- phosphate by the selective removel of the tirtyl and arylidene groups. The removal of these protective groups can be accomplished by a mild acid hydrolysis. For example, l-demethyl-l-(trityloxyethyl)-3,4-O- anisylideneclindamycin 2-phosphate on being heated with 80% acetic acid at 100 C. for one-half to one hour yields l'-demethyl-l '-(B-hydroxyethyl)clindamycin 2- phosphate. Acids such as formic, propionic, dilute hydrochloric and dilute sulfuric can also be used.

The desired 2-phosphate can be isolated from the reaction mixture by various techniques well known in the art or by following the special techniques illustrated with reference to clindamycin 2-phosphate. A suitable procedure is to subject the reaction mixture to gradient elution ion-exchange chromatography on quaternary ammonium resins such as Dowex l-X2. A linear gradient of water, pH 9, going to ammonium acetate pH 9 will separate l'-(,B-hydroxyethyl)-ldemethylclindamycin 2-phosphate from other by-products. The l-([3- hydroxyethyl)-ldemethylclindamycin 2-phosphate peak is collected and freeze-dried. Ammonium acetate is removed with heat and inorganic phosphate is removed by saturating an aqueous solution of l'-(B- hydroxyethyl)-l-demethylclindamycin 2-phosphate with ammonia gas to precipitate di-ammonium phosphate. l-(B-Hydr0xyethyl)-l -demethylclindamcyin 2-phosphate is obtained by freeze-drying the above aqueous solution to provide the mixed ammonium salts. Hemi-ammonium l-(B-hydroxyethyl)-l demethylclindamycin 2-phosphate is obtained by heating the above salt at 100 for three hours. The zwitterionic form of l'-(B-hydroxyethyl)-l'-demethylclindamycin 2-phosphate free of ammonia is obtained by heating the ammonium salt at ll8-l20 for 8-24 hours under high vacuum and crystallizing the zwitterionic form.

An alternative procedure is to remove the inorganic phosphates before the acid-hydrolysis. This has the advantage that the l'-(B-hydroxyethyl)-l-demethylclindamycin Z-phosphate sometimes can be crystallized directly without the necessity of going through the ammonium salt form.

The novel compounds of the invention are amino acids and can exist in a protonated or a non-protonated form according to the pH of the environment. At low pH the compounds exist in the acid-addition salt form, at a higher pH in a zwitterion form, and at a still higher pH in a metal salt form. The latter can be a neutral salt (two equivalents of base for each mole of l'-(B- hydroxyethyl)-l'-demethylclindamycin 2-phosphate), or a hemi salt (one-half equivalent of base for each mole of l-(B-hydroxyethyl)-ldemethylclindamycin 2-phosphate). By addition of appropriate amounts of suitable acids and bases, any of these various forms can be isolated. The acid addition salts include those of hydrochloric, sulfuric, phosphoric, acetic, succinic, citric, lactic, maleic, fumaric, pamoic, cholic, palmitic, mucic, comphoric, glutaric, glycolic, phthalic, tartaric, lauric, stearic, salicylic, 3-phenylsalicylic, phenylsalicylic, B-methylglutaric, ortho-sulfobenzoic, cyclohexanesulfamic cyclopentanepropionic. 1,2- cyclohexanedicarboxylic, 4-cyclopentanepropionic, l,2cyclohexanedicarboxylic, 4- cyclohexenecarboxylic, octadecenylsuccinic, octenylsuccinic, methanesulfonic, benzenesulfonic, dimethyldithiocarbamic, cyclohexylsulfamic, hexadecylsulfamic, octadecylsulfamic, sorbic, undecylenic, octyldecylsulfuric, picric, benzoic, cinnamic, and like acids. Acid and neutral salts include the alkaline metal (including ammonia) and alkaline earth metal (including magnesium) salts obtained by neutralizing an acid form with the appropriate base, for example, ammonium hydroxide, sodium and potassium hydroxides, or alkoxides, calcium, or magnesium hydroxides, and the like. The acid and netural salts also include amine salts obtained by neutralizing an acid form with a basic amine, for example, mono-, di-, and trimethylamines, mono-, di-, and triethylamines, mono-, di-, and tripropylamines (isoand normal), ethyldimethylamine, benzyldiethylamine, cyclohexylamine, benzylamine, dibenzylamine, N,N-dibenzylethylenediamine, bis-(ortho-methoxy-phenylisopropyl)-amine, and like lower-aliphatic, lower-cycloaliphatic, and loweraraliphatic amines, the lower-aliphatic and lowercycloaliphatic radicals containing up to and including eight carbon atoms; heterocyclic amines such as piperidine, morpholine, pyrrolidine, piperazine, and the lower-alkyl derivatives wherein lower alkyl contains one to eight carbon atoms, inclusive thereof such as lmethylpiperidine, 4-ethylmorpholine, l-isopropylpyrrolidine, 1,4-dimethylpiperazine, l-n-butylpiperidine, Z-methylpiperidine and lethyl2-methylpiperidine; amines containing water solubilizing or hydrophilic groups such as mono-, di-, and triethanolamines, ethyldiethanolamine, n-butyl-mono-ethanolamine, Z-aminol-butanol, 2-amino-2-ethyl-l ,3-propanediol, 2-amino-2-methyl-l-propanol, tris-(hydroxymethyl)- aminomethane (THAM), phenylmonoethanolamine, p-tertiaryamylphenyldiethanolamine, and galactamine, N-methylglucamine, N-methylglucosamine, ephedrine, phenylephrine, epinephrine, and procaine; tetraethylammonium hydroxide; and guanidine. The various forms can be used interchangeably but for most purposes the zwitterion form, THAM and the hemiammonium salt forms are preferred.

STEP IV The protective groups can be removed by hydrolysis, preferably, a mild acid hydrolysis. For example, protected 2-acylates or 2-phosphates on being heated with 80% acetic acid at 100 C. for 10 to min. yield the corresponding l-(B-hydroxyethyl)-l -demethylclindamycin 2-acylate or 2-phosphate compounds. Acids such as formic, propionic, dilute hydrochloric and dilute sulfuric can also be used.

The desired 2-acylate or 2-phosphate can be isolated from the reaction mixture by various techniques well known in the art. The 2-acylates or 2-phosphates so prepared are easily isolated as the hydrochloride salt by precipitation with a non-solvent such as acetone or ether. The compounds are usually isolated in a pure state by this method although if necessary recrystallization may be achieved from water or acetone plus a small amount of water.

The following preparations are illustrative of the method of preparing the acylate or phosphate compounds of the present invention.

Preparation 1 l'-Demethyl-l-(B-hydroxyethyl)-3,4- isopropylidineclindamycin One hundred grams of l-demethyl-l '-(B- hydroxyethyl)- clindamycin, 100 g. of p-toluenesulfonic acid hydrate and 6 l. of acetone are stirred at 25 for 60 hours. The unreacted starting material is removed by filtration and the filtrate adjusted to ph 7 with 5% Nal-lCO solution. The acetone is removed under vacuum and the aqueous phase extracted with Cl-lCl The CHCl extracts are evaporated under vac uum to give a residue which si purified by chromatography over silica gel using a solvent system composed of Cl-lCl :MeOH (6:1). The product fractions are identified by tlc, combined and evaporated to give 34 g. of l-demethyl-1-(B-hydroxyethyl)-3,4-isopropylidineclindamycin in 31% yield.

Preparation ll l-Demethyl-l -(trityloxyethyl)-3,4- isopropylidineclindamycin A mixture of 34 g of 1-demethyl-l-(B- hydroxyethyl)- 3,4-isopropylidineclindamycin, 1 15 g. of chlorotriphenylmethane, l 1. of acetone and 200 ml. of triethylamine is heated at reflux for 4 hours. Skellysolve B (l l.) is then added and the reaction mixture allowed to cool to 25. The precipitate of triethylamine HCl is removed by filtration and discarded. The filtrate is evaporated under vacuum and the residue purified by chromatography over silica gel using a solvent system composed of Skellysolve Bzacetone (2:1). The product fractions are identified by tlc, combined and evaporated to give g. of l-demethyl-l'(trityloxyethyl)- -3,4-isopropylidineclindamycin in 40 yield. Preparation lII 1'-(B-hydroxyethyl)clindamycin 2- palmitate .HCl Hydrate A solution of 6.0 g. of l-demethyl-l (trityloxyethyl)-3,4-isopropylidineclindamycin, 120 ml. of methylene chloride and 0.6 ml. of pyridine is stirred at 5 and 5.0 g. of palmitoyl chloride added. The reaction mixture is stirred at for 18 hours. Ethonal (50 ml.) is then added, the reaction mixture stirred for minutes and evaporated to dryness under vacuum. The residue is dissolved in a mixture of 60 ml. of HOAc and 10 ml. of H 0 and heated at 95 for 30 minutes. Water (60 m1.) is then added and the reaction mixture allowed to stand at 25 for 1 hour before filtering and discarding the solid material. The filtrate is evaporated to dryness under vacuum and the residue partitioned between dilute NaHCO and CHCl The CHCl phase is evaporated to dryness under vacuum and the residue purified by chromatography over silica gel using a solvent system composed of CHCl :MeOH (6:1 The product fractions are identified by tlc, combined and evaporated to dryness under vacuum to give the desired product in the form of the free base. This material is converted to its HCl salt, decolorized with Darco G-60 in MeOH, filtered and evaporated under vacuum to give 2.0 g. of the final product, l-demethyll-(/3- hydroxyethyl)clindamycin 2palmitate .HCl hydrate, as a waxy solid in 35% yield.

Analysis:

C, 57.59; H, 9.11; N, 3.84; S. 4.39;Cl. 9.72. Found (Corrected for H O):

C. 57.97; H, 9.29; N. 3.79; S, 4.39; Cl, 9.70. [a] "2" +79 (c, 0.8890).

Preparation IV l-Demethyl-l-(B-hydroxyethl)clin damycin 2-cyanoethylphosphate A mixture of 40 g. of l-demethyl-l -(trityloxyethyl)- 3,4-isopropylidine clindamycin, 400 ml. of a 1N pyridine solution of pyridinium cyanoethylphosphate, 160 g. of dicyclohexylcarbodiimide and l l. of pyridine is stirred under N at 25 for 60 hours. Water (300 ml.) is then added, stirred well, and the reaction mixture cooled at 5 for 18 hours. The precipitate is removed by filtration, washed with 400 ml. of pyridine and the combined filtrate and washings evaporated to dryness under vacuum. The residue is dissolved in 500 ml. of dimethylformamide and evaporated to dryness under vacuum. The residue is dissolved in 400 ml. HOAc and 100 ml. water and heated at for 30 minutes and then evaporated to dryness under vacuum. The residue is dissolved in 300 ml. of dimethylformamide and evaporated to dryness under vacuum. The residue is shaken with 300 ml. of EtOH, filtered and the filtrate evaporated to dryness. The residue is shaken with ml. EtOH plus 200 ml. water at 25 for 1 hour, filtered and the filtrate evaporated to dryness under vacuum. The residue is purified by chromatography over silica gel using a solvent system composed of CHCl :MeOH:H O (4:311). The product fractions are identified by tlc analysis, combined and evaporated under vacuum to give 30 g. of l'-demethyl-l-(/3-hydroxyethyl)clindamycin 2-cyanoethylphosphate in 94% yield. Preparation V l'-Demethyl-1-(B-hydroxyethyl)clindamycin 2-phosphate hydrate A mixture of 30 g. of 1'-demethy1-l '-(B- hydroxyethyl)-clindamycin 2-cyanoethy1phosphate, 500 ml. of concentrated NH OH and l l. of water is stirred at 25 for 24 hours. The reaction mixture is filtered and the filtrate evaporated under vacuum to a volume of about 1 1. This solution is freeze dried and the residue dissolved in l l. of water and passed through a column of 1,400 g. of Dowex l X 8 resin, 20-50 mesh, acetate form. The column is washed with 2 l. of water and the product then eluted from the resin with 3% HOAc solution. The effluent is monitored by tlc and the product fractions combined and freeze dried. The residue is crystallized from acetone-water to give 9.5 g. of white crystalline product of 1-demethyl-l -(B- hydroxyethyl)-clindamycin 2-phosphate hydrate (a 35% yield) of m.p. l94-l96.

Analysis:

Calcd for C H CIN O PS .(X) H O C, 42.65; H, 6.78; N. 5.24; S, 5.99; CI, 6.63; P, 5.79.

Found (Corrected for water):

C, 42.85; H, 6.60; N. 5.33; S. 5.86; Cl. 6.5l: P, 5.99.

The compounds of the Formula I have clindamycinlike antibacterial activity, i.e., similar spectrum, but unexpectedly show a high concentration in the urinary tract, i.e., the kidney and upper and lower urinary tract thereby providing an effective treatment for bacterial infections of the upper and lower urinary tract as well as treatment of L-forms or mycoplasma in the kidney.

The compounds can be administered orally, parenterally, rectally and topically. The acylates are particularly advantageous for oral administration for reasons of taste, and the phosphates, are preferred for parenteral administration.

Urinary tract infections such as cystitis, pyelonephritis and pyelitis when due to causative organisms, such as E. coli, S. aureus, enterococci and strains of Klebsiella, Aerobacter, Proteus and Pseudomonas.

The dosage in unesterifled or unphosphorylated free base equivalents, i.e., wherein X is hydrogen, for such treatment can be from 50 mg. to 5,000 mg. daily or calculated on a weight basis from about mg./kg. to 50 mg./kg. body weight daily.

The compositions of the present invention are presented for administration to humans and animals in unit dosage forms, such as tablets, capsules, pills, powders, granules, sterile parenteral solutions or suspensions, and oral solutions or suspensions, and oil-water emulsions containing suitable quantities of a compound of formula I or its pharmacologically acceptable salts.

For oral administration either solid or fluid unit dosage forms can be prepared. For preparing solid compositions such as tablets, the principal active ingredient is mixed with conventional ingredients such as talc, magnesium stearate, dicalcium phosphate, magnesium aluminum silicate, calcium sulfate, starch, lactose, acacia, methylcellulose, and functionally similar materials as pharmaceutical diluents or carriers. The tablets can be laminated or otherwise compounded to provide a dosage form affording the advantage of prolonged or delayed action or predetermined successive action of the enclosed medication. For example, the tablet can comprise an inner dosage and an outer dosage component, the latter being in the form of an envelope over the former.

Alternatively, the two component system can be utilized for preparing tablets containing two or more incompatible active ingredients. Wafers are prepared in the same manner as tablets, differing only in shape and the inclusion of sucrose or other sweetener and flavor. In their simplest embodiment, capsules, like tablets, are prepared by mixing the antibiotic with an inert pharmaceutical diluent and filling the mixture into a hard gelatin capsule of appropriate size. In another embodiment, capsules are prepared by filling hard gelatin capsules with polymeric acid coated beads containing the antibiotic. Soft gelatin capsules are prepared by machine encapsulation of a slurry of the antibiotic with an acceptable vegetable oil, light liquid petrolatum or other inert oil.

Fluid unit dosage forms for oral administration such as syrups, elixirs, and suspensions can be prepared. The water-soluble forms can be dissolved in an aqueous vehicle together with sugar, aromatic flavoring agents, and preservatives to form a syrup. An elixir is prepared by using a hydro-alcoholic (ethanol) vehicle with suitable sweeteners such as sugar and saccharin. together with an aromatic flavoring agent.

Suspensions can be prepared of the insoluble forms is an aqueous vehicle with the aid of a suspending agent such as acacia, tragacanth, methylcellulose and the like.

For parenteral adminstration, fluid unit dosage forms are prepared utilizing the antibiotic and a sterile vehicle, water being preferred. The antibiotic, depending on the form and concentration used, can be either suspended or dissolved in the vehicle. In preparing solutions the water-soluble antibiotic can be dissolved in water for injection and filter sterilized before filling into a suitable vial or ampul and sealing. Advantageously, adjuvants such as a local anesthetic, preservative and buffering agents can be dissolved in thevehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum. The dry lyophilized powder is then sealed in the vial and an accompanying vial of water for injection is supplied to reconstitute the liquid prior to use. Parenteral suspensions are prepared in substantially the same manner except that the antibiotic is suspended in the vehicle instead of being dissolved and sterilization cannot be accomplished by filtration. The antibiotic can be sterilized by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the antibiotic.

The term unit dosage form as used in the specification and claims refers to physically discrete units suitable as unitary dosages for human subjects and animals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with the required pharmaceutical diluent, carrier or vehicle. The specifications for the novel unit dosage forms of this invention are dictated by and directly dependent on (a) the unique characteristics of the active material and the particular therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such as active material for therapeutic use in humans and animals, as disclosed in detail in this specification, these being features of the present invention. Examples of suitable unit dosage forms in accord with this invention are tablets, capsules, pills, troches, suppositories, powder packets, granules, wafer, cachets, teaspoonfuls, tablespoonfuls, dropperfuls, ampuls, vials, segregated multiples of any of the foregoing, and other forms as herein described.

In addition to the administration of a compound of Formula I as the principal active ingredient of compositions for the treatment of the conditions described herein, the said compound can be included with other types of compounds to obtain advantageous combinations of properties. Such combinations include a compound of Formula I with antibiotics such as spectinomycin, chloramphenicol, tetracyclines (e.g., tetracycline, oxytetracylcine and chlortetracycline), penicillin, erythromycin novobiocin, kanamycin, streptomycin, neomycin, polymyxin, bacitracin, nystatin, and endomycin to broaden the bacterial spectrum of the composition and for synergistic action against particular bacteria; steroids having anti-inflammatory activity such as hydrocortisone, prednisolone, methylprednisolone, fluprednisolone and the like; analgesics such as aspirin, sodium salicylate, (acetylsalicylic acid)- anhydride, acetaminophen and salicylamide; antihistamines, such as chlorpheniramine maleate, diphenhydramine, promethazine, pyrathiazine, and the like; sulfas, such as sulfadiazine, sulfamethazine, sulfamerazine, sulfacetamide, sulfadimethyloxazole, sulfamethizole, and the like; antifungals, such as undecylenic acid, sodium propionate, salicylanilide, sodium caprylate, and hexetidine; and the vitamins.

A compound of the Formula I is compounded with a suitable pharmaceutical carrier in unit dosage form for convenient and effective administration. In the preferred embodiments of this invention, the dosage units contain a compound of Formula I in 25, 50, 100, 250, and 500 mg. amounts for systemic treatment; 0.5 to 50% w/v for parenteral or topical treatment. The dosage of compositions containing a compound of Formula l and one or more other active ingredients is to be determined with reference to the usual dosage of each such ingredient.

The following examples are illustrative of the best mode contemplated by the inventors for carrying out their invention and are not to be construed as limiting.

EXAMPLE 1 CAPSULES One thousand two-piece hard gelatin capsules for oral use, each containing 25 mg. of l-(B- hydroxyethyl)-l-demethylclindamycin are prepared from the following types and amounts of materials:

IWB-hydroxyethyl l demethylclindamycin 25 gm. Corn Starch [50 gm. Talc 75 gm. Magnesium stearate 2.5 gm.

EXAMPLE 2 CAPSULES One thousand two-piece hard gelatin capsules for oral use, each containing I mg. of 1-(,B- hydroxyethyl)-1'-demethylclindamycin Z-phosphate and 250 mg. of tetracycline hydrochloride, are prepared from the following types and amounts of ingredi ents:

2-phosphate 100 gm. Tetracycline hydrochloride 250 gm. Talc gm. Magnesium stearatc 2.5 gm.

The ingredients are thoroughly mixed and then encapsulated in the usual manner.

The foregoing capsules are useful for the treatment of pyelonephritis in adult humans by the oral administration of 1 capsule every 6 hours.

Using the procedure above, capsules are similarly prepared containing 1-(fl-hydroxyethyl)-l-demethylclindamycin 2-phosphate and each of the following antibiotics in place of tetracycline by substituting 250 gm. of such other antibiotic for tetracycline, chloroamphenicol, oxytetracycline, chlortetracycline, fumagillin, erythromycin, streptomycin, dihydrostreptomycin and novobiocin. When a penicillin, such as potassium pencillin G, is to be used in place of tetracyline, 250,000 units per capsule is employed.

Such combination products are useful for the systemic treatment of mixed kidney infections in adult humans by the oral administration of 1 capsule every 6 hours.

EXAMPLE 3 Tablets One thousand tablets for oral use, each containing 250 mg. of 1-(B-hydroxyethyl)-l-demethylclindamycin are prepared from the following types and amounts of materials:

demethylclindamycin 250 gm. Lactose 125 gm. Corn starch 65 gm. Magnesium stearate 2.5 gm. Light liquid petrolatum 3 gm.

The ingredients are thoroughly mixed and slugged. The slugs are broken down by forcing through a number sixteen screen. The resulting granules are then compressed into tablets, each tablet containing 250 mg. of l'-(B-hydroxyethyl)-l -demethylclindamycin.

The foregoing tablets are useful for treatment of pyelitis in adult humans by oral administration of 1 tablet every 4 hours.

EXAMPLE 4 TABLETS One thousand oral tablets, each containing mg. of 1'-(B-hydroxyethyl)-l-demethylclindamycin and a total of 250 mg. (83.3 mg. each) of sulfadiazine, sulfamerazine, and sulfamethazine, are prepared from the following types and amounts of materials:

demethylclindamycin I00 gm. Sulfadiazine 833 gm. Sulfamerazine 83.3 gm. Sulfamethazine 83.3 gm. Lactose 50 gm. Corn Starch 50 gm. Calcium stearate 2.5 gm. Light liquid petrolatum 5 gm.

The ingredients are thoroughly mixed and slugged. The slugs are broken down by forcing through a number sixteen screen. The resulting granules are then compressed into tablets, each containing [00 mg. of l- (B-hydroxyethyU-l'-demethylclindamycin and a total of 250 mg. (83.3 mg. each) of sulfadiazine, sulfamerazine, and sulfamethazine.

The foregoing tablets are useful for treatment of urinary tract infections by the oral administration of4 tablets first and then 1 every six hours.

The triple sulfas in the above formulation can be replaced by 250 gm. of sulfamethylthiadiazole or 250 gm. of sulfacetamide.

EXAMPLE 5 ORAL SYRUP One thousand ml. of an aqueous suspension for oral use, containing in each 5 ml. dose, one-half gram of total sulfas and 100 mg, of l'-(B-hydroxyethyl)-ldemethylclindamyci 2-palmitate is prepared from the following types and amounts of ingredients:

demethylclindamycin 2- palmitate gm. Sulfadiazine 33.3 gm Sulfamerazinc 33.3 gm. Sulfamethazine 33.3 gm. Citric acid 2 gm. Benzoic acid 1 gm. Sucrose 700 gm. Tragacanth 5 gm. Lemon oil 2 ml Deionized water q.s. 1000 ml.

The citric acid, benzoic acid, sucrose, tragacanth, and lemon oil are dispersed in sufficient water to make 850 ml. of solution. The l'-(B-hydroxyethyl)-l'- demethylclindamycin-2-palmitate and finely powdered sulfas are stirred into the syrup until uniformly distributed, Sufficient water is added to make 1,000 ml.

The composition so prepared is useful in the treatment of cystitis in adult humans at a dose of 1 teaspoonful 4 times a day.

EXAMPLE 6 PARENTERAL SOLUTION A sterile aqueous solution for intramuscular use, containing in 1 ml. 75 ml. of l-(B-hydroxyethyl)-l demethylclindamycin 2-phosphate is prepared from the following types and amounts of materials:

demethylclindamycin 2-phosphate 75 gm. Lidocainc hydrochloride 4 gm. Methylparaben 2.5 gm. Propylparaben 0.17 gm. Water for injection q.s. I000 ml.

The ingredients are dissolved in the water and the solution sterilized by filtration. The sterile solution is filled into vials and the vials sealed.

EXAMPLE 7 PARENTERAL SOLUTION A sterile aqueous solution for intramuscular use, containing in 1 ml. 100 mg. of 'l -(B-hydroxyethyl)-l demethylclindamycin -phosphate, as the Na salt is prepared from the following types and amounts of ingredients:

l'-(B-hydroxyethyl)-l demethylclindamycin 2- phosphate I00 gm. Sodium hydroxide 10% Solution q.s. Water for injection q.s. 1000 ml.

The l'-(B-hydroxyethyl)-l '-demethylclindamycin 2-ph0sphate is added to the water and sufficient sodium hydroxide added to form a solution and the solution sterilized by filtration. The sterile solution, in the amount of 2 ml., is aseptically filled into sterile vials and frozen. The water is removed under high vacuum and the vials containing the lyophilized powder are sealed. Just prior to use, sufficient sterile water for injection to make 2 ml. of solution is added to the vial.

EXAMPLE 8 SUPPOSITORY, RECTAL One thousand suppositories, each weighing 2.5 gm. and containing 100 mg. of l-(B-hydroxyethyl)-l demethylclindamycin Z-phosphate are prepared from the following types and amounts of ingredients:

demethylclindamycin 2- phosphate l00 gm. Polymyxin B sulfate (l0.000

units/mg.) l.25 gm. Methylprednisolone 1 gm. Ethyl aminobenzoate gm. Zinc oxide 62.5 gm. Propylene glycol 162.5 gm. Polyethylene glycol 4000 q.s. 2500 gm.

cmcrhOH ,1, cm K H Halo 1/ I N B1 II or the acid addition salts thereof wherein Halo is chlorine, bromine, or iodine, X is a member selected from the group consisting of hydrogen, an acyl of an aliphatic carboxylic acid having from 2 to 18 carbon atoms, inclusive,

the zwitterion thereof or the hemi salt thereof; R is alkyl of not more than 4 carbon atoms wherein R is alkyl of not more than 8 carbon atoms in association with a pharmaceutical carrier.

2. A composition according to claim 1 wherein the compound is present in a unit dosage amount of from 25 to 500 mg.

R1 ll I or the acid addition salts thereof wherein Halo is chlorine, bromine, or iodine, X is a member selected from the group consisting of hydrogen, an acyl of an aliphatic carboxylic acid having from 2 to 18 carbon atoms, inclusive,

the zwitterion thereof or the hemi salt thereof; R is alkyl of not more than 4 carbon atoms wherein R is alkyl of not more than 8 carbon atoms in association with a pharmaceutical carrier.

7. A process according to claim 6 wherein the compound is administeredat a dosage amount of from 50 to 5,000 mg. daily.

8. A process according to claim 6 wherein the compound administered is l-(Bhydroxyethyl)l demethylclindamycin.

9. A process according to claim 6 wherein the compound administered is l-(B-hydroxyethyl)-1- demethylclindamycin 2-phosphate.

10. A process according to claim 6 wherein the com pound administered is l-(,B-hydroxyethyl)-l demethylclindamycin 2'palmitate. 

1. A PHARMACEUTICAL COMPOSITION COMPRISING A COMPOUND OF THE FORMULA:
 2. A composition according to claim 1 wherein the compound is present in a unit dosage amount of from 25 to 500 mg.
 3. A composition according to claim 1 wherein the compound is 1''-( Beta -hydroxyethyl)-1''-demethylclindamycin.
 4. A composition according to claim 1 wherein the compound is 1''-( Beta -hydroxyethyl)-1''-demethylclindamycin 2-phosphate.
 5. A composition according to claim 1 wherein the compound is 1''-( Beta -hydroxyethyl)-1''-demethylclindamycin 2-palmitate.
 6. A process for treating bacterial infections comprising the systemic administration of a compound of the formula:
 7. A process according to claim 6 wherein the compound is administered at a dosage amount of from 50 to 5,000 mg. daily.
 8. A process according to claim 6 wherein the compound administered is 1''-( Beta -hydroxyethyl)-1''-demethylclindamycin.
 9. A process according to claim 6 wherein the compound administered is 1''-( Beta -hydroxyethyl)-1''-demethylclindamycin 2-phosphate.
 10. A process according to claim 6 wherein the compound administered is 1''-( Beta -hydroxyethyl)-1''-demethylclindamycin 2-palmitate. 